Saturday, March 24, 2012

More March Torch Data

While today's high of "just" 61 was the coolest day we've had since March 16th, the morning low of 52 degrees is going to tie a record warm low for the date.  the daily low of 50 just grazed below the record warm low of the date by two degrees.  Still warm, still above 50.  More info on both of those below.  The thirteen day period between March 12th and 24th is one of the most remarkable stretches of warmth we've experienced in March.  Here's a litany of data to sum it up:
  • Average daily temperature over the 13 days was 59.9 degrees, which is "normal" for the thirteen day period between April 27th and May 9th.
  • Philadelphia was 15.8 degrees above average during this time frame.  The average high was 16.4 degrees above average (69.8 versus 53.4) and the average low "just" 15.1 (49.9 versus 34.8) degrees.
  • One record high (80) on March 23rd.
  • Four Three record warm lows set or tied (54, 3/13; 55, 3/20; 58, 3/21; 52, 3/24).
  • Five consecutive highs of 70 or above in Philadelphia -- one shy of the March record set in 1990.
  • Eight days of 70 or above in streak and nine for the month of March.  The nine ties the all-time record for most 70+ days, set in 1921 and 1945.
  • Five consecutive lows of 50 or above (3/20 through 3/24).  This ties the current record from 3/27-3/31/1998 for most mornings of 50 or above in a row.
  • Seven mornings through today with a low of 50 or above, tying the record for most 50+ lows in the month of March with 1913.

We had four days where our low was equal to our "average" high, if not higher -- 3/14, 3/20, 3/21, and 3/22.  Simply put, our weather the past thirteen days was arguably the most May-like in March that we've seen since could argue ever if you wanted to and I wouldn't put up a fight.

Some of the data is remarkable.  Yeah, it can get to 80 in March even before it did this year.  However, past warmth was often fleeting and often a bad tease as reality quickly struck.   However, seeing two weeks worth of temperatures more typical for late April, early May is something that is pretty uncommon.   Adding in the fact that many of the nights had fog and low clouds, preventing cooling of the atmosphere, and the data skews further in a warmer direction.    Most of the past warmth we've seen didn't have the level of humidity, consistently, that this one streak did.  '98's streak was humid as well...'95 had some humidity but not on this level, nor did 1990's.  This streak was remarkable enough at the surface, but would have probably been even more remarkable if we didn't have a backdoor front for two days nor had three days of fog that prevented runs farther into the 70's.

The bad news for everyone who bought flowers at your local retailer this weekend is that there is the potential for a couple of frosts, if not freezes, over the next week.  Yes, the calendar still says March and if the average low at this time of the year is 35, 36 degrees at the Airport a not-too-colder than average night can still yield frost in your backyard and on your tulips.